Pepperl+Fuchs KFD0-CS-Ex2.54 Isolated Barrier Repeater

Technical Overview

2-channel loop-powered isolated barrier for intrinsic safety, transmitting 1-20mA analog and superimposed SMART signals from hazardous areas. SIL 2 rated.

Key Features

2-channel isolated barrier
24 V DC supply (loop powered)
SMART fire alarm input
Current input 1 mA ... 20 mA
Up to SIL 2 acc. to IEC/EN 61508
Provides control and signal transfer for SMART compatible fire and smoke alarm transmitters in hazardous areas
Digital signals (AC up to 6 V) can be superimposed on analog values and transferred bidirectionally
Removable terminals
DIN rail mount
IP20 degree of protection

Technical Specification Matrix

Parameter	Value
Signal Type	Analog input
Safety Integrity Level (SIL)	SIL 2 acc. to IEC/EN 61508
Supply Voltage	24 V DC (loop powered)
Power Loss	< 0.2 W for Uin = 24 V, Io = 20 mA
Input Current Range	1 mA ... 20 mA
Output Current Range	0 ... 20 mA
Transmission Range (Voltage)	4 ... 26 V DC / 0 ... 6 Vpp AC
Electrical Isolation	Input/Output safe electrical isolation acc. to IEC/EN 60079-11, voltage peak value 375 V
Electromagnetic Compatibility (EMC)	Directive 2014/30/EU, EN 61326-1:2013, NE 21:2006
Ambient Temperature	-20 ... 60 °C (-4 ... 140 °F)
Degree of Protection	IP20
EU-Type Examination Certificate	BAS 00 ATEX 7087
Physical Weight (kg)	0.1
Dimensions L x W x H (cm)	11.5 x 2 x 10.7

Industrial Applications

1. Fire and Gas Detection in Chemical Processing Plants

This isolated barrier is perfectly suited for safely connecting SMART-compatible fire and gas alarm transmitters located in hazardous areas (e.g., Zone 1 or 2 chemical storage or processing units) to the safe area control system. Its intrinsic safety design prevents the release of ignition-capable energy into explosive atmospheres, while the 2-channel analog input facilitates robust monitoring.

Problem Solved

Ensures safe and reliable signal transmission from critical fire/gas detectors in explosive chemical environments to control systems, preventing ignition sources and maintaining continuous safety monitoring as required for SIL 2 applications.

Intrinsic safetyHazardous areaZone 1Chemical processingFire detectionGas detectionSMART sensorsSIL 2Analog input (1-20mA)

2. Industrial HVAC Control in Potentially Explosive Environments

In industrial settings like paint booths, solvent storage, or certain pharmaceutical manufacturing facilities, HVAC systems require sensors (e.g., temperature, humidity, air quality) to operate within potentially explosive atmospheres. This repeater can safely interface 1-20mA analog sensor signals from these hazardous zones to a safe area PLC or DCS, enabling precise climate control while adhering to explosion protection standards.

Problem Solved

Provides an intrinsically safe interface for analog sensor signals from HVAC systems in hazardous industrial environments, allowing for accurate environmental control without introducing explosion risks, supported by the device's IP20 rating for protected indoor installation and -20 to 60°C operating range.

Hazardous areaHVAC controlIntrinsic safety barrier1-20mA analog signalTemperature sensorAir quality monitoringExplosion protectionZone 2IP20

3. Remote Monitoring of Tank Levels in Fuel Depots and Refineries

For fuel storage tanks in depots or refineries where flammable liquids create hazardous atmospheres, level transmitters require intrinsically safe connections. This 2-channel isolated barrier can reliably transmit 1-20mA analog level signals from two SMART-enabled level transmitters situated in Ex-rated zones to a central control room, facilitating safe and accurate inventory management.

Problem Solved

Enables intrinsically safe, reliable transmission of analog level data from field devices in flammable liquid storage areas to a remote control system. The loop-powered design simplifies installation in hazardous locations, and the SIL 2 rating supports high-integrity overfill prevention systems.

Fuel depotTank level monitoringHazardous locationIntrinsic safety1-20mA current loopSMART HART communicationEx-zoneSIL 2